Merge branch 'vlada/xfce-notg' of git://github.com/vcunat/nixpkgs

This branch refactors xfce and updates it to 4.10. I had been hoping to
find someone besides Vlada to test this (I don't use xfce), but no one
has come forward yet in 2 weeks so if this breaks something they can
make an issue or fix it. It all looks good by inspection.

pkgs/build-support/fetchurl/mirrors.nix

@@ -223,6 +223,20 @@ rec {
     ftp://ftp.nara.wide.ad.jp/pub/X11/GNOME/
   ];
 
+  xfce = [
+    http://archive.xfce.org/
+    http://mirror.netcologne.de/xfce/
+    http://archive.se.xfce.org/xfce/
+    http://archive.be.xfce.org/xfce/
+    http://mirror.perldude.de/archive.xfce.org/
+    http://archive.be2.xfce.org/
+    http://ftp.udc.es/xfce/
+    http://archive.al-us.xfce.org/
+    http://mirror.yongbok.net/X11/xfce-mirror/
+    http://mirrors.tummy.com/pub/archive.xfce.org/
+    http://xfce.mirror.uber.com.au/
+  ];
+
   # X.org.
   xorg = [
     http://xorg.freedesktop.org/releases/